How to Service a Water Heater

Watch How to Service a Water Heater on YouTube.

Learn how to service your electric water heater with Ben Goheen, master plumber with 15 years of experience and owner of The Neighborhood Plumber. Get expert tips on the importance of yearly water heater maintenance to get the most life out of your system. Plus, discover how RWC brands work together to complete a water heater setup.

Preparations

Before beginning any maintenance, prioritize safety.

  • Turn off the power: For electric units, locate and switch off the corresponding double-pole breaker in your electrical panel. If your panel isn't marked, look for double-pole breakers.
  • Turn off the water supply: Close the main water shut-off valve to the water heater.
  • Beware of hot water: The water draining from the heater will be very hot, so exercise caution.

Water Heater Accessories

Tools You'll Need

  • Adjustable wrenches
  • Garden hose
  • Sediment bucket
  • Paper towels
  • Pressure gauge  

Flushing Out Sediment: Step-by-Step

Flushing your water heater removes sediment buildup, which can improve efficiency and water quality.

  1. Connect the hose: Attach your garden hose to the drain valve at the bottom of the water heater.
  2. Open the drain valve: Slowly open the drain valve.
  3. Break the vacuum: To allow the water to drain efficiently, you need to break the vacuum in the tank. If your water heater has a mixing valve (like a Cash Acme Tank Booster), simply opening a hot water faucet may not work. In this case, carefully open the temperature and pressure (T&P) relief valve lever. You will hear air entering the tank as the water begins to drain consistently.
  4. Drain the tank: Allow the water heater to drain completely. On new units, this will be quick, but older units with more sediment may drain slowly. If the water flow becomes restricted, close the T&P valve, turn the water supply back on briefly, and reopen the drain and T&P valve to dislodge sediment.
  5. Rinse the tank: Once the tank is empty, turn the main water supply back on while the drain valve is still open. This will rinse out any remaining sediment from the bottom of the tank. Then, let it run for 20-30 seconds.
  6. Close the drain valve: Turn off the water supply and close the drain valve.
  7. Refill the tank and bleed air: Open a few of your water faucets, especially upstairs faucets, to allow air to escape as the tank refills. It's crucial to get all the air out to prevent damage to the heating elements. Wait until a steady stream of water comes out of the faucet, indicating all air has been purged.
  8. Turn power back on: Once the tank is full and all air is bled, turn the power back on at the breaker. The water heater will take about an hour to fully heat the water. 

Key Water Heater Components Explained

Understanding your water heater's components can help you ensure its optimal performance and safety.

  • Cash Acme Tank Booster: This device mixes cold water with hot water to increase the effective volume of hot water by up to 50%. It allows the tank to store water at a higher temperature (e.g., 150°F) and then mixes it down to a safer output temperature (e.g., 120°F).
  • Eastman Thermal Expansion Tank: This tank prevents excessive pressure buildup in your plumbing system as water heats and expands. You can check if it's working by tapping it (a hollow sound means it's good) or by pressing the valve stem (air should come out, not water). The air pressure in the tank should match your house's water pressure. These tanks should be properly mounted to the wall to prevent any possible damage.
  • Cash Acme Temperature and Pressure (T&P) Relief Valve: This is a critical safety device that opens to release water if the tank's temperature exceeds 210°F or if the water pressure in the system goes above 150 PSI, preventing the heater from exploding or pipes from breaking. It's vital to ensure this valve is working, especially on older units. There are different types depending on your water heater model.
  • Anode Rod: This rod protects the inside of your water heater tank from corrosion. Minerals in the water will attack the anode rod instead of the tank lining. Some flexible anode rods are available that can be installed on the hot water nipple, effectively adding a second anode rod and potentially extending the heater's life.

Additional Maintenance Tips

  • Visual Inspection: After flushing, visually inspect all connections for any leaks, staining, or rust.
  • Check Water Pressure: Regularly check your house's water pressure using a pressure gauge on a boiler drain or outdoor faucet. Ideal pressure is typically between 50 and 70 PSI. If your pressure is consistently above 70 PSI, consult a professional to check or install a pressure regulating valve (PRV).  

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